Portable paving material mixing apparatus

ABSTRACT

A portable paving material mixing apparatus includes a material hopper, a rotatable mixing drum, and a discharge bed, all configured to be supported on a vehicle trailer. A burner heats material within the mixing drum. Embodiments of the mixing apparatus include a rejuvenator application system suitable for hot mix asphalt, cold mix asphalt, hot in-place recycling, and asphalt based concrete mixing. The apparatus rapidly processes a batch of material sufficient to fill 5-7 potholes, has sufficient carrying capacity to process multiple mixer batches, and stores prepared material in the discharge bed while the next batch is being prepared in the mixing drum. The apparatus enables a more efficient, less equipment-intensive paving repair process without the need for a separate millings loader or hot box.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the filing benefit under 35 U.S.C. § 119(e) ofU.S. Provisional Application No. 62/424,205, filed 18 Nov. 2016, whichis hereby incorporated by reference.

TECHNICAL FIELD

The present invention pertains generally to systems and methods forsurface paving, and more particularly to a portable paving materialmixing apparatus.

BACKGROUND OF THE INVENTION

Portable paving material mixers, also known as asphalt recyclers, areknown in the art. Existing systems have several drawbacks which makethem unsuitable for continuous, low cost, or small scale operations.

Existing systems to not have the ability to transport enough asphaltmillings or other aggregate to fill the mixing drum multiple times. As aresult, they must return to an aggregate storage site in between loads,or additional loads must be brought to the repair site by a dump truckor other heavy equipment.

Existing mixers do not have the capability to store a batch of mixed andheated material ready for application on the mixer itself. If an entirebatch is not immediately used, it must be transferred from the mixer toan asphalt hot box for storage so that the mixer can process the nextload.

In some existing mixers, the mixing drum itself is heated, and thematerial is heated via contact with the drum while being mixed. Thisheating method is quite slow, often resulting in down time for thepaving crew. Other mixers use a direct material heating method, but arenot configured to discharge prepared material without moving the heateraway from the mixing drum. This method disrupts continuous operation ofthe mixer.

There is a need in the field for a portable asphalt paving mixer whichallows continuous operation, processes multiple batches of materialwithout additional equipment, applies rejuvenator or other additivesduring mixing, and provides more rapid turn-around times per batch.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a portable paving material mixingapparatus which rapidly processes a batch of material sufficient to fill5-7 potholes, has sufficient carrying capacity to process multiple mixerbatches, and stores prepared material in a discharge bed for applicationwhile the next batch is being prepared. The apparatus enables a moreefficient, less equipment-intensive paving repair process without theneed for a separate millings loader or hot box.

Embodiments of the mixing apparatus include a rejuvenator applicationsystem suitable for hot mix asphalt, cold mix asphalt, hot in-placerecycling, and asphalt based concrete mixing. The mixing apparatus maybe assembled on a tandem axle trailer for towing by a vehicle with a10,000 lb or greater towing capacity.

In an embodiment, a portable paving material mixing apparatus includes ahopper having an open top configured to receive aggregate. The hopper ispositionable to transfer a portion of the aggregate to a rotatablemixing drum through an aperture in a front end of the drum. A burner isconfigured to heat material within the mixing drum. A discharge bed ispositioned to receive mixed paving material from the mixing drum andconfigured for direct transfer of the mixed paving material to a pavedsurface for repairs. The hopper, mixing drum, and discharge bed areconfigured to be simultaneously supported on a vehicle trailer. Furtherprovided is a system including the vehicle trailer.

In accordance with another embodiment, the discharge bed is configuredfor transfer of mixed paving material to the paved surface while themixing drum is rotating. This feature permits continuous operation ofthe apparatus, as a first batch of paving material may be applied forrepairs while a second batch is being prepared in the mixing drum. Inanother embodiment, the discharge bed is positioned below the mixingdrum. In another embodiment, the discharge bed is heated.

In accordance with another embodiment, the mixing drum has a rear endand is positioned with a downward inclination from the front end towardthe rear end. In another embodiment, the front end of the mixing drum isin contact with at least one wheel, and the wheel is configured to bemounted to the trailer.

In accordance with another embodiment, a channel is mounted between thehopper and the mixing drum and positioned such that aggregate istransferred from the hopper to the mixing drum via the channel. Inanother embodiment, the hopper has a chute configured to transferaggregate therethrough, and the channel is shaped and dimensioned toreceive at least a portion of the chute.

In accordance with another embodiment, the burner is mounted below thechannel and positioned so that when the burner is lit flame from theburner projects into the drum through the aperture.

In accordance with another embodiment, the mixing drum includes anaccess panel in a sidewall through which material may exit the mixingdrum to be received in the discharge bed.

In accordance with another embodiment, the apparatus includes anautomatic rejuvenator application system having a reservoir configuredto hold asphalt rejuvenator and a sprayer in fluid connection with thereservoir. The sprayer is positioned to transfer asphalt rejuvenator tothe mixing drum through the aperture. In another embodiment, therejuvenator application system is configured to dispense multiple typesof rejuvenator based upon the paving application.

In accordance with another embodiment, the hopper has a hopper capacity,the mixing drum has a mixing drum capacity, and the hopper capacity isat least three times greater than the mixing drum capacity. This featureenables refilling the mixing drum multiple times from a single hopperload. In another embodiment, the total capacity of the apparatus,including the hopper, mixing drum, and discharge bed, is at least 3000lbs.

Other embodiments, in addition to the embodiments enumerated above, willbecome apparent from the following detailed description, taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of the portable paving material mixing apparatusand method of use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a portable paving material mixingapparatus.

FIG. 2 is a right side view of the apparatus.

FIG. 3 is a reduced front view of the apparatus with some components ofa trailer removed.

FIG. 4 is a reduced rear view of the apparatus.

FIG. 5 is a top plan of the apparatus.

FIG. 6 is a perspective view of the apparatus.

FIG. 7 is a cross-sectional view along the line VII-VII of FIG. 5.

FIG. 8 is a perspective view of the apparatus with some componentsremoved.

FIG. 9 is a view of a control panel of the apparatus.

LIST OF DRAWING REFERENCE NUMERALS

-   1 trailer-   2 jack stand-   3 hopper-   4 access panel 43 channel-   5 propane tank 44 chain-   7 control panel 45 stack-   10 drum 46 drum wheels-   11 rejuvenator pump 48 deflectors-   12 hydraulic pump-   13 burner 60 batteries-   14 hitch receiver-   15 heating torch-   16 aperture-   17 rejuvenator reservoir-   18 rejuvenator sprayer-   19 water tank-   20 cone holder-   21 safety light-   22 winch-   23 lifts-   24 drum motor-   25 protective cage-   27 hose reel-   28 rejuvenator spray button-   29 burner timer-   30 heater power switch-   31 hopper controls-   33 power management system-   34 charging port-   40 hydraulic cylinder-   41 hydraulic fluid reservoir-   42 chute-   43 channel-   44 chain-   45 stack-   46 drum wheels-   48 deflectors-   50 discharge bed-   60 batteries

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIGS. 1-6, there are illustrated left and rightside, reduced front and rear, top plan, and perspective views,respectively, of a portable paving material mixing apparatus. The shownembodiment of the apparatus includes a hopper 3, a rotatable mixing drum10, a burner configured to heat material within the mixing drum, and adischarge bed 50 positioned to receive mixed paving material from themixing drum. The apparatus is shown assembled on a cooperating trailer1. The drum is shielded by a protective cage 25, which is removed fromthe views of FIGS. 3-6 for clarity. The terms front, rear, left, andright are used herein with respect to the forward direction of thetowing vehicle.

Hopper 3 holds aggregate, such as asphalt millings, and has an open topwhich is readily accessible for loading, such as with a scoop or bucketloader. In one embodiment, the length of hopper 3 as measured from theside is sufficiently long to receive material from a bucket loader; forexample hopper 3 may be open along a 60″, 66″, or 72″ length. In anotherembodiment, hopper 3 has a 3000 lb capacity. Hopper 3 is positionable totransfer aggregate into drum 10. In the shown embodiment, hopper 3 ispositioned by operation of a hydraulic pump 12 in connection withhydraulic cylinders 40. Hydraulic fluid may be stored in a reservoir 41.

FIG. 7 is a cross-sectional view along the line VII-VII of FIG. 5,showing hopper 3 in alternate positions for loading aggregate into drum10. Hydraulic pump 12 (see FIG. 2) drives one or more telescopinghydraulic cylinders 40 to position hopper 3 from resting on trailer 1(position A) to a raised position (B, in dashed lines) along thedirectional arrow.

Hopper 3 includes a chute 42 projecting toward drum 10 so that whenhopper 3 is in the raised position, B, aggregate is poured from thehopper into drum 10 through an aperture 16 in the front end of the drum.In an embodiment, drum 10 has a 700 lb operating capacity.

Hopper 3 has a sufficient capacity to refill the drum multiple times. Inother embodiments, the hopper capacity is at least three times greaterthan the mixing drum capacity. After loading drum 10, hopper 3 islowered back to resting position A.

As shown in FIG. 7, drum 10 is preferably positioned at a downward angleθ toward the rear of trailer 1. After aggregate is loaded into drum 10,the drum may be rotated to force the aggregate toward the back of thedrum. This process clears the front of the drum, allowing the additionof more aggregate if desired.

In an embodiment, a channel 43 is mounted between hopper 3 and mixingdrum 10. Channel 43 is positioned such that aggregate being transferredfrom the hopper is poured through channel 43 into the mixing drum. Inanother embodiment, channel 43 is shaped and dimensioned to receive atleast a portion of chute 42 when the hopper is positioned to transferaggregate. In other embodiments, aggregate may be poured directly fromthe hopper into the mixing drum.

FIG. 8 is a perspective view of the apparatus with some components, suchas the hopper and structural components, removed for clarity. FIG. 8shows a burner 13 which is positioned to heat material within mixingdrum 10. In an embodiment, burner 13 is propane fueled; several propanetanks 5 may be seen in FIGS. 1 & 2. In another embodiment, burner 13 maybe diesel fueled. Burner 13 is positioned in front of drum 10 forheating material in drum 10 through aperture 16. When in use, flamesfrom burner 13 project into drum 10, directly and rapidly heatingmaterial inside drum 10. Drum 10 is rotated while burner 13 is firing toevenly heat the material. Direction of rotation is indicated by thearrow of FIG. 4. In an embodiment, several material lifts 23 are mountedon the internal wall of drum 10 to provide proper agitation of thematerial. Due to the angle θ of the drum (see FIG. 7) the drum is angledaway from the burner, and flames from the burner do not come in contactwith the material. In one embodiment, flames from burner 13 projectbetween about 18-242″ into drum 10.

The burner is operated for a period of time sufficient to bring thematerial in the drum to a temperature suitable for application. In oneembodiment, material is brought from ambient temperature to 400° F.after 2-5 minutes of burner operation. Burner operating times requiredwill vary based on ambient temperature and amount of material beingheated. In one embodiment the burner is turned off automatically by atimer 29 (FIG. 9).

In another embodiment, the burner may be mounted on a pivoting burnerarm positionable out of the way of the drum when aggregate is beingloaded and in front of drum for heating material.

In FIGS. 1-7 a stack 45 is located above channel 43. Stack 45 serves todeflect material being poured into channel 43, and also functions as anexhaust stack when burner 13 is in operation.

Referring now to FIG. 4, a drum motor 24 is operatively connected todrum 10. In the shown embodiment the drum motor is connected by a chain44 to a planetary gear system or sprocket to rotate drum 10 (chain 44shown surrounded by a cage in FIGS. 1 & 2). The front end of drum 10rests upon drum wheels 46 (best shown in FIG. 8), which support the loadof drum 10 and permit it to rotate (as indicated by the arrow) whendriven by the drum motor.

Two wheels 46 are present in the shown embodiment, however, more orfewer wheels could be used.

FIGS. 6 & 8 show a removable access panel 4, or door, in the sidewall ofdrum 10. When access panel 4 is removed and drum 10 is rotated, heatedmaterial is discharged from the drum through the opening left by removalof access panel 4. Again, the angle θ of drum 10 serves to move materialtoward the rear of the drum and out to discharge bed 50 (see FIG. 4).Drum 10 may be rotated in alternating directions to more efficientlydischarge material. One or more deflectors 48 may be provided to directmaterial into discharge bed 50. Access panel 4 may also be removed whenmaterial is not being discharged, such as to permit temperaturemonitoring of the material with an infrared thermometer.

In one embodiment, the discharge bed 50 is heated to keep material readyfor application. This feature eliminates the need to transfer mixedpaving material to a separate hot box for storage prior to application.In one embodiment, the discharge bed has a 500 lb carrying capacity. Inthe shown embodiment, the discharge bed is positioned below the mixingdrum and the mixing drum may be rotated while the discharge bed is full.This configuration permits continuous operation of the system, in thatwhile a first batch of paving material is being laid down from thedischarge bed a second batch may be heated in the mixing drum.

Material may be transferred from the discharge bed directly to thepaving surface. In one embodiment the discharge bed is about 18 inchesabove the ground for easy manual transfer of material. Material may thenbe spread and compacted if desired for the application.

In an embodiment, the apparatus includes an automated rejuvenatorapplication system including a rejuvenator pump 11, rejuvenatorreservoir 17, and rejuvenator sprayer 18 (see FIGS. 1 & 7). Rejuvenatoris stored in reservoir 17 and pumped by pump 11 to sprayer 18 whichsprays rejuvenator onto the material in drum 10 through aperture 16 (seeFIG. 8). In an embodiment, reservoir 17 is a bucket that is easilyinterchanged when more rejuvenator is needed. When material in drum 10has been heated to the appropriate temperature, for example about 275°F., an operator activates the rejuvenator spray which evenly distributesrejuvenator onto the material in drum 10. Drum 10 is then rotated for aperiod of time sufficient to evenly blend rejuvenator with the pavingmaterial, for example 3 minutes.

In an embodiment, sprayer 18 is configured to permit the spray to reachmaterial in the back of drum 10. Sprayer 18 may protrude slightlythrough aperture 16 to ensure that all rejuvenator is transferred todrum 10. Sprayer 18 is located out of the way of both burner 13 and theregion toward the rear of the drum where material tumbles when drum 10is rotated.

In an exemplary embodiment, the rejuvenator is comprised of 5 gallons oflight oil (such as a plant based oil) and between 8-12 ounces of asphaltcutback, which includes a petroleum solvent.

In another embodiment, the rejuvenator system includes a plurality ofpumps 11 and reservoirs 17 for different applications, such as hotin-place asphalt recycling, cold-mix asphalt patching, or mixingconcrete with asphalt millings as an aggregate. Alternatively, solidadditives, such as binders, may be added to the material in drum 10through aperture 16 or access panel 4.

Referring again to FIGS. 1 & 2, an embodiment of trailer 1 includes ajack stand 2 and a hitch receiver 14. Other equipment may be stored ontrailer 1, such as a heating torch 15, a safety cone holder 20, a watertank 19 and hose reel 27, a winch 22, batteries 60, a power roller, atool rack, a fire extinguisher, or the like.

Safety lights 21 are mounted to cage 25. The system may automaticallyoperate the safety lights or generate a warning sound when the burner isin operation or when the mixing drum is rotating.

FIG. 9 shows an embodiment of a control panel 7 (see also FIGS. 2 & 6)which is readily accessible for curbside operation of the portablemixer. Controls available at the panel include heater power switch 30and burner timer 29, hopper controls 31, rejuvenator spray activationbutton 28, a power management system 33, and a charging port 34.Multiple rejuvenator spray buttons are provided in some embodiments.Control panel 7 may also include an emergency shutoff switch.

Further provided is a system wherein the apparatus is deliveredassembled and mounted to the trailer.

In terms of use, a method of operating a portable paving material mixingapparatus includes (refer to FIGS. 1-9):

-   -   a. providing a portable paving material mixing apparatus        including:        -   i. a vehicle trailer 1;        -   ii. a hopper 3 having an open top configured to receive            aggregate and being positionable to transfer a portion of            the aggregate to a rotatable mixing drum 10 through an            aperture 16 in a front end of the drum;        -   iii. a burner 13 configured to heat material within the            mixing drum;        -   iv. the drum having an access panel 4 in a sidewall through            which material may exit the mixing drum to be received in a            discharge bed 50;        -   v. the discharge bed positioned to receive mixed paving            material from the mixing drum and configured for direct            transfer of the mixed paving material to the paved surface;            and,        -   vi. the hopper, mixing drum, and discharge bed supported on            the vehicle trailer;    -   b. providing aggregate;    -   c. loading the aggregate into the hopper;    -   d. positioning the hopper to transfer an appropriate amount of        aggregate from the hopper to the drum and returning the hopper        to a resting position;    -   e. rotating the drum to force aggregate toward a rear end of the        drum;    -   f. operating the burner so that a flame projects into the drum        but does not come in direct contact with material in the drum,        for a period of time sufficient to heat the material to a        predetermined application temperature;    -   g. rotating the drum while the burner is on;    -   h. stopping rotation of the drum and opening the access panel;    -   i. rotating the drum to discharge material from the drum to the        discharge bed; and,    -   j. moving material from the discharge bed to the paving surface.

The method further including:

-   -   repeating steps (d) and (e) until a desired quantity of        aggregate is in the drum.

The method further including:

-   -   simultaneously performing steps (g) and (j).

The method further including:

-   -   after (i), heating material within the discharge bed.

The method further including:

-   -   in (a), the apparatus further including:        -   a reservoir 17 configured to hold asphalt rejuvenator; and,        -   a sprayer 18 in fluid connection with the reservoir, the            sprayer positioned to transfer asphalt rejuvenator to the            mixing drum through the aperture; and,    -   before (f): providing asphalt rejuvenator in the reservoir and        operating the sprayer to transfer the asphalt rejuvenator to the        mixing drum.

The embodiments of the apparatus and method of use described herein areexemplary and numerous modifications, combinations, variations, andrearrangements can be readily envisioned to achieve an equivalentresult, all of which are intended to be embraced within the scope of theappended claims. Further, nothing in the above-provided discussions ofthe apparatus and method should be construed as limiting the inventionto a particular embodiment or combination of embodiments. The scope ofthe invention is defined by the appended claims.

We claim:
 1. A portable paving material mixing apparatus configured toprepare aggregate for repairing a paved surface, the apparatuscooperating with a vehicle trailer, the apparatus comprising: a hopperhaving an open top configured to receive aggregate and beingpositionable to transfer a portion of the aggregate to a rotatablemixing drum through an aperture in a front end of the drum; a burnerconfigured to heat material within the mixing drum; a discharge bedpositioned to receive mixed paving material from the mixing drum andconfigured for direct transfer of the mixed paving material to the pavedsurface; and, the hopper, mixing drum, and discharge bed configured tobe simultaneously supported on the vehicle trailer.
 2. The apparatus ofclaim 1, wherein the discharge bed is configured for transfer of pavingmaterial to the paved surface while the mixing drum is rotating.
 3. Theapparatus of claim 2, wherein the discharge bed is positioned below themixing drum.
 4. The apparatus of claim 1, wherein the mixing drum has arear end and is positioned with a downward inclination from the frontend toward the rear end.
 5. The apparatus of claim 4, wherein the frontend of the mixing drum is in contact with at least one wheel, and thewheel is configured to be mounted to the trailer.
 6. The apparatus ofclaim 1 further including: a channel mounted between the hopper and themixing drum and positioned such that aggregate is transferred from thehopper to the mixing drum via the channel.
 7. The apparatus of claim 6further including: the hopper having a chute configured to transferaggregate therethrough; and, the channel being shaped and dimensioned toreceive at least a portion of the chute.
 8. The apparatus of claim 6wherein the burner is mounted below the channel and positioned so thatwhen the burner is lit flame from the burner projects into the drumthrough the aperture.
 9. The apparatus of claim 1 further including: anaccess panel in a sidewall of the mixing drum through which material mayexit the mixing drum to be received in the discharge bed.
 10. Theapparatus of claim 1 further including: a reservoir configured to holdasphalt rejuvenator; and, a sprayer in fluid connection with thereservoir, the sprayer positioned to transfer asphalt rejuvenator to themixing drum through the aperture.
 11. The apparatus of claim 1, whereinthe hopper has a hopper capacity, the mixing drum has a mixing drumcapacity, and the hopper capacity is at least three times greater thanthe mixing drum capacity.
 12. The apparatus of claim 1 having a totalcapacity of at least 3000 pounds.
 13. The apparatus of claim 1, whereinthe discharge bed is heated.
 14. A portable paving material mixingapparatus configured to prepare aggregate for repairing a paved surface,the apparatus comprising: a vehicle trailer; a hopper having an open topconfigured to receive aggregate and being positionable to transfer aportion of the aggregate to a rotatable mixing drum through an aperturein a front end of the drum; a burner configured to heat material withinthe mixing drum; a discharge bed positioned to receive mixed pavingmaterial from the mixing drum and configured for direct transfer of themixed paving material to the paved surface; and, the hopper, mixingdrum, and discharge bed supported on the vehicle trailer.
 15. Theapparatus of claim 14 further including: the discharge bed beingconfigured to transfer paving material to the paved surface while themixing drum is rotating; the hopper having a hopper capacity, the mixingdrum having a mixing drum capacity, and the hopper capacity being atleast three times greater than the mixing drum capacity; a reservoirconfigured to hold asphalt rejuvenator; and, a sprayer in fluidconnection with the reservoir, the sprayer positioned to transferasphalt rejuvenator to the mixing drum through the aperture.
 16. Amethod for preparing paving material to repairing a paved surface, themethod comprising: a. providing a portable paving material mixingapparatus including: i. a vehicle trailer; ii. a hopper having an opentop configured to receive aggregate and being positionable to transfer aportion of the aggregate to a rotatable mixing drum through an aperturein a front end of the drum; iii. a burner configured to heat materialwithin the mixing drum; iv. the drum having an access panel in asidewall through which material may exit the mixing drum to be receivedin a discharge bed; v. the discharge bed positioned to receive mixedpaving material from the mixing drum and configured for direct transferof the mixed paving material to the paved surface; and, vi. the hopper,mixing drum, and discharge bed supported on the vehicle trailer; b.providing aggregate; c. loading the aggregate into the hopper; d.positioning the hopper to transfer an appropriate amount of aggregatefrom the hopper to the drum and returning the hopper to a restingposition; e. rotating the drum to force aggregate toward a rear end ofthe drum; f. operating the burner so that a flame projects into the drumbut does not come in direct contact with material in the drum, for aperiod of time sufficient to heat the material to a predeterminedapplication temperature; g. rotating the drum while the burner is on; h.stopping rotation of the drum and opening the access panel; i. rotatingthe drum to discharge material from the drum to the discharge bed; and,j. moving material from the discharge bed to the paving surface.
 17. Themethod of claim 16 further including: repeating steps (d) and (e) untila desired quantity of aggregate is in the drum.
 18. The method of claim16 further including: simultaneously performing steps (g) and (j). 19.The method of claim 16 further including: after step (i), heatingmaterial within the discharge bed.
 20. The method of claim 16 furtherincluding: in (a), the apparatus further including: a reservoirconfigured to hold asphalt rejuvenator; and, a sprayer in fluidconnection with the reservoir, the sprayer positioned to transferasphalt rejuvenator to the mixing drum through the aperture; and, before(f): providing asphalt rejuvenator in the reservoir and operating thesprayer to transfer the asphalt rejuvenator to the mixing drum.